1. Field of the Invention
The present invention relates to a remote control apparatus and method. The present invention relates in particular to a point type remote control apparatus and a method thereof which selects a certain point on the display screen corresponding to a positional coordinate calculated according to phase differences a plurality of signal receiving sensors.
2. Description of the Prior Art
Television receivers and computer systems have been currently provided with an on-screen display system or computer application software for displaying execution points on the display screen using a window system, and selecting a desired point by moving a cursor on the display screen. In such a case, the position of the cursor is controlled by a remote control or a wireless mouse.
FIG. 1 shows a structure of a conventional remote control apparatus. Referring to FIG. 1, the conventional remote control apparatus comprises a direction key (i.e., joy stick) 1 for moving a cursor to a desired point on the display screen and selecting the point, a pulse generator 2 for generating a pulse signal including a digital code corresponding to the direction of the chosen point, a carrier generator 3 for generating a carrier which modulates the pulse signal to enable it to be transmitted through the air, a current amplifier 4 for modulating the pulse signal with the carrier and amplifying the modulated pulse signal, and an infrared-transmitting diode 5 driven by the pulse signal outputted from the current amplifier 4 for transmitting infrared rays into the air.
The conventional remote control apparatus has also been provided with a signal receiving sensor 6 for receiving the transmitted infrared rays, a signal amplifier 7 for amplifying the infrared ray signals received by the signal receiving sensor 6, an envelope detector 8 and a comparator 9 for removing the carrier from the output signal of the signal amplifier 7 to reproduce only the pulse signal, and a pulse analyzer 10 for analyzing a direction code from the reproduced pulse signal to obtain information about the point direction.
In the conventional remote control apparatus constructed as described above, if a user selects a desired direction by utilizing the joy stick 1, the pulse generator 2 generates a pulsed digital code signal corresponding to the desired direction of the point. This pulse signal enters the current amplifier 4 with a carrier generated from the carrier generator 3 to be modulated and amplified, and is then applied to the infrared-transmitting diode 5. Accordingly, the infrared-transmitting diode 5 transmits the infrared rays into the air.
The transmitted infrared rays enter the signal receiving sensor 6 and are amplified by the signal amplifier 7 in order to compensate for transmission loss through the air. The carrier is removed from the amplified signal by the envelope detector and the comparator 9, so that only the pulse signal is extracted. The extracted pulse signal is analyzed into a code of pulse form by the pulse analyzer 10, and thus information about the moving direction of the point can be obtained according to the analyzed code. Accordingly, if a user operates the Joy stick continuously, the above operation is repeatedly performed and thus information about the direction of the point can be obtained at regular intervals. Therefore, it is possible to move the point to any desired position on the display screen.
However, such conventional remote control apparatus has the drawback that it is inconvenient to manipulate the joy stick 1, which must be continuously operated in order to move the cursor to the desired position on the display screen. Moreover, if a user intends to move the point to a distant position, this requires significant moving time. In addition, due to the directivity of a receiving sensor, the joy stick 1 should be manipulated only when the transmitter 40 is exactly focused on the position of the signal receiving sensor 6.
Meanwhile, a point type remote control apparatus for improving the disadvantage of the conventional point type remote control apparatus is disclosed in the applicant's prior application of the U.S. patent application 08/093,350 filed on the Jul. 16, 1993.
Referring to FIG. 2 and FIG. 3A, the conventional remote control apparatus comprises a transmitter 40 and a receiver/controller 50.
The transmitter 40 comprises a switch SW, a pulse generator 12 for generating a pulse signal whale the switch SW is turned on, a carrier generator 13 for generating a carrier which modulates the pulse signal to allow the pulse signal to be radiated through the air, a current amplifier 14 modulating and amplifying the pulse signal with the carrier, and an infrared-transmitting diode 15 driven by the output of the current amplifier 14 for transmitting the infrared pulse signal.
The receiver/controller 50 comprises signal receiving sensors 16a to 16d positioned at four corners of the display screen 11 for receiving the pulse signal transmitted from the infrared-transmitting diode 15, signal amplifiers 17a to 17d for amplifying the weak pulse signals received by each of the signal receiving sensor 16a to 16d, envelope detectors 18a to 18d for removing the carrier from the output signals of the respective signal amplifiers 17a to 17d and providing level signals corresponding to the intensities of the pulse signals received by the respective signal receiving sensors 16a to 16d, a multiplexer 19, a sample and holder 20, and an analog/digital (A/D) converter 21 connected in series for converting the output levels of the envelope detectors 18a to 18d into digital values, a coordinate calculator 22 receiving the output of A/D converter 21 as an input thereof for calculating the present coordinate on the display screen pointed by the transmitter 40, a main processor 23 for recognizing the point corresponding to the coordinate calculated by the coordinate calculator 22 and displaying it on the display screen, and a control logic section 24 for controlling the timing for driving the above elements 19, 20, 21 and 23.
The operation and efficacy of the apparatus constructed as above will be explained in detail.
With reference to FIG. 3B, the signal receiving sensors 16a to 16d are respectively positioned at four corners of the display screen 11 as shown in FIG. 4A, which enables the point to move on a two-dimensional plane.
If the switch Sw is turned on while the transmitter 40 points to a desired position on the display screen 11, the pulse generator 12 generates a pulse signal until the switch SW is turned off. The pulse signal then enters the current amplifier 14 with a carrier generated from the carrier generator 13. Then, the current amplifier 14 modulates the pulse signal with the carrier and amplifies the modulated pulse signal to apply to the infrared-transmitting diode 15 for transmitting the pulse signal and the carrier.
The amplified pulse signal is transmitted into the air by the infrared-transmitting diode 15 and is received by the signal receiving sensors 16a to 16d in the receiver/controller 50. At this time, the intensities of each pulse signal received by the signal receiving sensors 16a to 16d vary according to the direction of the transmitter 40, that is, according to the angle between the transmitter 40 and each of the signal receiving sensor 16a to 16d.
The pulse signals received by the signal receiving sensors 16a to 16d as stated above are respectively amplified by the signal amplifiers 17a to 17d and then enter the envelope detectors 18a to 18d respectively. Then, the envelope detectors 18a to 18d remove the carrier from the amplified signals and provide envelope-detected signals corresponding to the intensities of the pulse signals respectively received by the signal receiving sensors 16a to 16d.
The envelope-detected signals provided from the envelope detectors 18a to 18d successively pass through the multiplexer 19, the sample and holder 20, and the A/D converter 21 to be converted into a digital value and then enter the coordinate calculator 22. Accordingly, the coordinate calculator 22 calculates the currently pointed position coordinate on the display screen 11.
FIG. 4B shows an exemplified display screen for selecting from a menu when the above-described apparatus is embodied in an audio/video system. As shown in FIG. 4B, if the transmitter 40 used to direct a desired machine portion, where a machine selection menu composed of a television receiver (TV), a video cassette recorder (VCR), a compact disc player (CDP) and a laser disc player (LDP) is displayed on the screen 11 divided into four portions, one signal receiving sensor nearest to the portion pointed by the transmitter 40 among the signal receiving sensors 16a to 16d positioned at four corners of the display screen 11 receives the strongest signal. Accordingly, the coordinate calculator 22 calculates the position coordinate corresponding to the machine portion pointed to by the transmitter 40.
Meanwhile, if the display screen 11 is divided into eight or more portions due to an increase of menu functions, the coordinate calculator 22 calculates the position coordinate on the basis of one signal receiving sensor whose signal level is the highest among those of the signal receiving sensors 16a to 16d. For example, if the signal receiving sensor 16b in FIG. 4B has the highest signal level, the signal receiving sensor 16d has the lowest signal level. Accordingly, by utilizing the received signal levels of the respective signal receiving sensors 16a and 16c with respect to the signal receiving sensor 16b, excepting the signal sensor 16d, the position coordinate on the display screen 11 can be calculated by the coordinate calculator 22.
The main processor 23 displays the current point on the display screen 11 by matching the position coordinate calculated by the coordinate calculator 22 to the display screen 11.
The timing for driving the above elements 19, 20, 21 and 23 in the receiver/controller 50 is controlled by the control logic section 24.
Meanwhile, FIGS. 5A and 5B show different arrangements of the signal receiving sensors which are suitable to move a point along a one-dimensional straight line on the display screen 11, rather than on a two-dimensional plane. That is, as shown in FIGS. 5A and 5B, a pair of signal receiving sensors 16b and 16c, or 16a and 16b is positioned at the right and left or the top and bottom of the display screen 11 when it is necessary to move a point P in a straight line between the right and left or the top and bottom of the display screen 11. Therefore, the point P can be moved in the desired direction according to the differences in intensities of signals received by the pair of signal receiving sensors.
The operation of this modification is the same as that of the apparatus illustrated in FIGS. 4A and 4B.
However, the conventional point type remote control apparatus so far described determines the point corresponding to the positional coordinate calculated by the coordinate calculator 22, where the calculated coordinate is matched to the strongest signal achieved by comparing the only signal intensities received by the signal receiving sensors 16a to 16d positioned around the display screen 11. Thus, the conventional point type remote control apparatus those has the disadvantage that an erroneous determination of the coordinate might be made owing to a deviation of the radiation angle or distance between the transmitter 40 and the signal receiving sensors 16a to 16d.